The most significant cultural aspect of 玻璃 (bōli) in modern Chinese is not the material itself, but its metaphorical use to describe emotional fragility.
The term 玻璃心 (bōli xīn), literally “glass heart,” has become pervasive in Chinese internet culture. It functions as a powerful piece of slang used to describe a person, group, or even a nation that is perceived as being overly sensitive, thin-skinned, and unable to take criticism or jokes.
Comparison to Western Concepts: This is very similar to calling someone a “snowflake” or “thin-skinned” in American/Western culture. It carries a similarly dismissive and often critical connotation, implying that the person's emotional reaction is excessive and unwarranted.
Social and Political Usage: While it can be used casually between friends (“Don't be such a glass heart!”), it's frequently used in online political and social discourse. For example, if a foreign brand makes a perceived slight against China, Chinese netizens who react with outrage might be described by critics (both domestic and international) as having a “glass heart.” This highlights its role in navigating the complexities of modern nationalism and public opinion.